Bridge rectifiers are widely used in difference applications. A bridge rectifier is used to rectify an alternating current (AC) signal to a direct current (DC) signal. Conventional bridge rectifiers are shown in FIG. 1 and FIG. 2. FIG. 1 shows an example bridge rectifier 100 as a prior art. Bridge rectifier 100 comprises four diodes 101, 102, 103, and 104. Bridge rectifier 100 receives an AC signal through an input IN1 and an input IN2 and provides a rectified DC signal between an output OUT1 and an output OUT2. A capacitor C1 is coupled between output OUT1 and output OUT2. Capacitor C1 may be used to lessen a variation of the rectified output DC signal. FIG. 2 shows another bridge rectifier 200 as a prior art. Bridge rectifier 200 comprises four schottky diodes 201, 202, 203 and 204.
For high voltage application, voltage drops on the diodes are relatively small and have almost no influence on efficiency. However, for low voltage application, voltage drops on the diodes will result in a low efficiency. As a result, a bridge rectifier with lower voltage drop is needed to improve efficiency.